ML20198R376
| ML20198R376 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 10/29/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20198R375 | List: |
| References | |
| NUDOCS 9711130253 | |
| Download: ML20198R376 (4) | |
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1 A-UNITED STATES p
NUCLEAR RECULATORY COMMISSION WASHINGTON, D.C. SpeeHe01 l
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 99 TO FACILITY OPERATING LICENSE NO. DPR 22 i
NORTHERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263
1.0 INTRODUCTION
By letter dated November 25,1996, as supplemented December 12,1996, April 23, May 8, July 1, August 21, and September 29,1997, the Northem States Power Company (the licensee) requested an amendment to the Technical Specifications (TS) appended to Facility Operating License No. DPR 22 for the Monticello Nuclear Generating Plant (MNGP). The proposed amendment would revise the Minimum Critical Power Ratio (MCPR) safety limits based on the cycle-specific analysis of the current mixed core of GE11/GE10 fuel parameters.
The December 12,1996, letter provided an affidavit for the original application dated November 25,1996. The April 23, May 8 August 21, and September 29,1997, letters provided clarifying information in response to the staffs request for additional information. The July 1, 1997, letter provided a nonproprietary version of the April 23,1997, submittal. This information was within the scope of the original application and did not change the staffs initial proposed no significant hazards considerations determination. Therefore, renoticing was not warranted.
2.0 EVALUATION The licensee requested a change to the Monticello TS in accordance with 10 CFR 50.90. The proposed revision of TS 2.1.A and its associated Bases 2.1, TS 3.11.C, and TS 6.7 is described below. This revision is based on the cycle-specific analysis of the current mixed core of GE11/GE10 fuel parameters, and therefore the revision is effective until the end of operating cycle 18.
2,1 Revision to TS 2.1.A and Bases 2.1 The licensee has proposed to change the Safety Limit MCPR (SLMCPR) in TS 2.1.A-from 1.07 to 1.08 for two recirculation loop operation, and from 1.08 to 1.09 for single recirculation loop operation, when the reactor steam dome pressure is greater than 800 psia [ pounds per square inches absolute), and core flow is greater than 10% rated core flow. The licensee also proposed to change the associated TS Bases 2.1 to replace a numerical value of the SLMCPR by a phrase, "The values specified in TS 2.1.A."
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0 The staff has reviewed the proposed changes to TS 2.1.A and Bases 2.1, which are based on the j
analyecs performed using Monticello Cycle 18 cycle specific inputs and approved methodologies including GESTAR ll (NEDE 24011-P-A 11, Sections 1.1.5 and 1.2.5 [ proprietary information-not publicly available)), and NEDO 10985-A [ proprietary information-not publicly available),
January 1977 and found them to be acceptable. Because the R-factor methodology referenced in NEDE 24011-P-A 11 is not applicable to the part-length GE11 fuel, a revised R-factor i
methodology described in NEDC-32505P, "R-Factor Calculation Method for GE11, GE12 and GE13 Fuel," [ proprietary information-not publicly available) November 1995 was used. The 1
revised R-factor calculation method uses the same NRC-approved equation stated in GESTAR ll
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- (NEDE-24011 P-A) with the correction factors to account for the peaking factor effects due to the part length-rod design. The staff has reviewed the R-factor calculation method for GE11 fuel, the j
relevant information provided in the proposed Amendment 25 to GESTAR ll, NEDE-24011 (which j
is under staff review) and the supplemental information dated April 23 and May 8,1997, in response to the staff request for additionalinformation during a teleconference on March 18, l
1997, on the Monticello Cycle 18 SLMCPR calculation. Based on this review, the staff has found i
the revised R-factor methodology in NEDC-32505P acceptable for use at MNGP.
l The staff has also determined that the justification for analyzing and determining the SLMCPR of 1.08 for two recirculation loop operation and 1.09 for single loop operation for Monticello Cycle 18 i
with respect to the generic GE11 SLMCPR evaluation is acceptable because (1) MNGP Cycle 18 1
is not an equilibrium core; (2) MNGP Cycle 18 has a slightly flatter core MCPR distribution and l
bundle R factor distributions than the generic GE11 equilibrium core; (3) MNGP Cycle 18 is loaded with a higher latest reload average batch weight percent enrichment; (4) only eight SPC j
[Siemens Power Corporation) ATRIUM 9B assemblies (starting Cycle 17) are loaded in the core locations such that they have significant CPR margin relative to the limiting MCPR assemblies in i
the core; and (5) the result of the analysis using higher interim additive constant uncertainty for l
ATRIUM-9B fuel shows no impact on the proposed SLMCPR for MNGP Cycle 18. Therefore, the j
staff has concluded that the proposed SLMCPR (1.08 for two recirculation loop operation and 1.09 for single loop operation) will ensure that a sufficient margin to the fuel cladding integrity limit (i.e.,
that 99.9 percent of the fuel rods in the core avoid transition boiling) exists for MNGP Cycle 18.
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2.2 Revision to TS 3.11.C MCPR i
The proposed change to TS 3.11.C includes revising the first sentence to read:
"All MCPRs shall be greater than or equal to the MCPR operatina limits provided in the Core Operating Limits Report" to replace the existing statement which reads:
"The MCPR shall be greater than or equal to the limits provided in the Core Operating Limits Report."
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In addition, the proposed change also includes deletion of the second sentence which currently "The OLMCPR [ operating limit minimum critical power ratio) limit for one recireciation loop -
i operation is 0.01 higher than the comparable two loop value."
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I 3-4 These changes clarify the TS requirement for MCPR consistent with the changes to TS 2.1.A as
- described in Section 2.1 of this safety evaluation and provides for the relocation of OLMCPR for single recirculation loop operation to the COLR consistent with the COLR guidance in Generic Letter 88-16 " Removal of Cycle-Specific Parameter Limits From Technical Specifications," dated October 4,1988. Therefore, the staff finds these changes acceptable.
2.3
-TS 6,7 Core Operatina Limits Rooort (COLR) l The proposed change to TS 6.7 includes adding an asterisk to the first item on the list of documents in TS 6.7.b. to read:
l "NEDE 24011-P-A, ' General Electric Standard Application for Reactor Fuel' (the approved version at the time the reload analyses are performed)*"-
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and adding a footnote on TS page 249b that reads:
"* For cycle 18 only as approved in SE data >d i
The revision to TS 6.7.b. is to reflect the approved use of tne revised R-factor calculation method i
and will ensure that values for cycle-specific parameters are determined such that applicable limits l
(i.e., nuclear limits, transient analysis limits, and accident analysis limits) are met. Therefore, the staff finds these changes acceptable.
l In addition, the staff finds acceptable the correction of the spelling of the word "SER" in the licensee's proposed footnote to "SE."
Based on its review as documented above, the staff concludes that the proposed changes to the l
TS and Bases are acceptable for Monticello Nuclear Generating Plant Cycle 18 application since the changes are analyzed based on the NRC-approved methodologies and the conservative l
cycle-specific parameters for SLMCPR analysis are used.
i Also, on page 10 of the bases for Section 2.1, the licensee revised the wording " protection system j
safety settims" to " protection systems safety settings." The staff finds this clarifying change to the bases acceptable.
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3.0 STATE CONSULTATION
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In accordance with the Commission's regulations, the Minnesota State official was notified of the l
proposed issuance of the amendments. The State official had no comments, j
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The staff has j
determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant e
increase in individual or cumulative occupational radiation exposure. The Commission has 4
previously issued a proposed finding that the amendment involves no significant hazards
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consideration and there has been no public comment on such finding (62 FR 17238). The amendment also changes reporting or record keeping requirements. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(g) and (c)(10).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: T. Huang Date: October 29, 1997
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